Improvement in processes of preserving wood



PATENT OFFICE.

WILLIAM H. JONES, or ROCHESTER, NEW YORK.

IMPROVEMENT IN PROCESSES OF PRESERVING WOOD.

Specification forming part of Letters Patent No. 132,584, dated October 29, 1872.

To all whom it may concern:

Be it known that I, WM. H. JONES, of Rochester, in the county of Monroe and State of New York, have invented a certain Process for Preserving Wood, of which the following is a specification:

This invention consists of the process for preserving wood, as hereinafter described.

Grude coal-tar is placed in a retort and distilled. The first products of distillation, which are very light and ethereal in character, are passed off and are not available for this purpose. The heavier products, which come from the last distillation, are those which are used, and have a gravity of about 10 Baum, which will float water.

The pavin g-blocks, which are usually cut in lengths of about five or six inches, are fitted for the treatment without further preparation.

The distilled product is placed in a large tank having a furnace beneath, and'is raised to a boiling-heat. This heat is of sufficient intensity to retain the boiling capacity after the blocks are inserted. The blocks are applied quickly in this mass and boiled for a space of five minutes, more or less, which causes the wood to swell and the pores to open, and the pungent and penetrating properties of the liquid enter and follow the grain from end to end, thus'permeating every part of the wood. The blocks are removed quickly before becoming sodden or erisped by the heat, which would injure the fiber. In due time after the removal the liquid will penetrate and spread through all the textures of the Wood and become equalized, filling all the pores.

A necessary step in the process is to use only a given quality of the product of the distillation, viz, th atwhich approximates l0 Baum. A higher quality will etherealize and evaporate, leaving the pores still open, and thus fail to produce a preservative. A lower quality will. contain too much sediment, and obstruct the pores against a ready entrance of the liquid.

Another necessary step in the process is the boiling temperature of the liquid when the blocks are inserted. This produces a sudden swelling and expansion of the wood and opens the pores with rapidity, which a slow process of heating would not do. The quick removal, when the pores are filled, is also essential to prevent injury to the fiber.

The old process of treating wood to coal-tar in its crude state, or even artificially thinned below its natural state, is very imperfect to thoroughly impregnate the material. It contains a large amount of solid sediment, which cannot enter the wood and obstructs the entrance of the other parts. In fact, the solid matter and the liquid are so thoroughly combined that they will only enter together. The consequence is that wood treated with such material only becomes covered at the surface, with a very slight penetration.

In my process the solid matter is left behind in the distillation, and the product that passes over is simply a liquid which is free of these parts, which would obstruct the action, and which are really deleterious and useless as a preservative.

I do not confine myself to the treatment of pavingblocks alone in this way, but design to cover the treatment of all kinds of wood.

I claim- The process herein described fortreating wood, Yiz, by inserting the wood for a space of five minutes, more or less, in the product of coal-tar produced by distillation at a gravity approximating 10 Baum, said product being raised to boiling-heat at the time of insertion.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

WM. H. JONES.

Witnesses:

R. F. Oseoon, A. BAINE. 

